1. Field of the Invention
The present invention relates to a framework connecting device of a prefabricated building structure that is capable of connecting frameworks with each other when the prefabricated building structure is constructed.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Generally, frameworks, which constitute columns, rafters, and the like in all kinds of prefabricated building structures, such as warehouses, warehouse type buildings, stables, etc., are connected with each other by means of connection pieces, bolts and nuts and then covered with vinyl or finished with various exterior materials.
Until now, however, the frameworks of the prefabricated building structure are connected with each other by means of connection pieces having a shape of just a plate in such a manner as to be separated back and forth from each other and a plurality of bolts and nuts passed through the connection pieces, thus making it hard to perform the assembling work. Further, strength reinforcement is needed additionally in accordance with desired strengths of the prefabricated building structures, and specifically, the strength on the connected portion of the neighboring frameworks is substantially weak, so that the safety of the prefabricated building structure cannot be ensured reliably.
That is, if the columns, rafters and vertical rods constituting the prefabricated building structure are made by cutting the frameworks formed of just generally square pipes, the frameworks should be made of a substantially thick steel plate so as to obtain a desired strength, thus undesirably increasing the material cost and weight and further making it difficult to handle and construct the frameworks.
Furthermore, the front and rear connection pieces connecting the frameworks with each other are formed of just plates having different outer shapes according to the angles of encounter between the frameworks in such a manner as to be brought into close contact with the side surfaces of the frameworks, and after the end portions of the frameworks to be connected to each other are disposed between the front and rear connection pieces, next, the frameworks and the front and rear connection pieces are connected to each other by means of the plurality of bolts and nuts passed through the connection holes formed thereon. However, it is very complicated and hard to perform connection and fixation of the frameworks to the front and rear connection pieces by means of the bolts and nuts in the state where the connection holes formed on the frameworks and the front and rear connection pieces communicate with each other, thus remarkably reducing the work efficiency.
Additionally, even though the thicknesses of fit e front and rear connection pieces are increased to reinforce the strength of the connection portion of the frameworks and the plurality of bolts and nuts is used upon the connection, the connection portion of the frameworks may be deformed between the front and rear connection pieces due to the strong fastening of the bolts and nuts. Further, the strength on the connection portion of the frameworks formed of just square pipes becomes weak due to the connection holes formed thereon, thus failing to ensure the safety of the prefabricated building structure.
Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a framework connecting device of a prefabricated building structure that is capable of reducing the material cost and weight required for a framework having a desired strength, performing assembling work readily and easily, and reinforcing the strength on the connection portion of frameworks.